Pollinators are critical to the Nation's economy, food security, environment and health. Honey bee pollination alone adds more than $15 billion in value to agriculture crops each year. It also helps to improve public health by ensuring the availability of ample fruits, nuts and vegetables, which are part of a balanced diet. In addition, honey bee pollination enhances land conservation, which makes ecosystems more resistant to climate change and natural disasters.
But pollinators are struggling, particularly honey bees. In 2016, reported losses of all managed colonies in the U.S., amounted to 44.1 percent. The annual losses increased 3.5 percent from the previous year—the first year in which summer season losses exceeded winter season losses. As a result of the high rate of loss, beekeepers are working harder to replace and/or maintain their colonies.
The economic impact of bee colony loss is significant. The estimated direct cost to beekeepers alone totals $2 billion. The estimate assumes that 10 million hives have been lost at a conservative valuation of $200 each. Looking at just this past year, the estimated direct cost to beekeepers is almost $500 million. Another estimation approach based on lost agriculture output puts the economic burden much higher at more than $4.4 billion.
High colony loss rates require beekeepers to rapidly, and at substantial expense, rebuild their colonies, placing commercial beekeeping in jeopardy as a viable industry and threatening the crops dependent on honeybee pollination.
Despite challenging circumstances, commercial beekeepers have been somewhat successful at passing along the added costs of colony loss. For example, the cost of renting honey bees for almond growers rose from $51.99 per colony in 2003 to as much as $157.03 per colony in 2009.
In recent years, research has focused on the causes of colony loss or Colony Collapse Disorder (CCD), a phenomenon that occurs when worker bees leave an otherwise healthy colony. Research suggests that the declining bee population could be caused by the “combined stresses” of parasites, pesticides and habitat loss. However, now that some of the causes are known, finding ways to help minimize loss and achieve goals set forth in the National Strategy to Promote the Health of Honey Bees and Other Pollinators is critical. The strategy calls for reducing overwintering mortality to 15 percent within ten years. However, recent data show that winter loss rates are on the rise and well above the acceptable level. Overwintering motility increased 5.8 percentage points to 28.1 percent this past winter from 22.3 percent in the previous winter.
FIG. 1 illustrates that overwintering mortality, a key metric for determining the overall health of honey bees, is on the rise. The share of colonies lost during the 2015-2016 winter was 28.1 percent, which significantly exceeds the sustainable level of 15 percent of commercially managed colonies in the U.S.
Current approaches to increase overall colony health have focused primarily on monitoring chemical composition using sampling techniques and gas chromatography. However, the method provides only a snapshot of chemical composition and does not monitor in real-time the changes to chemical composition and how those changes affect the overall health of honey bee colonies. Less scientific methods are also being deployed. Many commercial beekeepers have accepted high colony loss rates of about a quarter of their bees on average and are having to rebuild their hives from scratch. The rebuilding process typically takes about two months and involves transferring bees from a healthy colony to a new hive. These bees produce a hatch of baby bees and food to support them. A queen bee is required, and one queen now costs upwards of $25. It is not unusual for commercial beekeepers to spend hundreds of thousands of dollars per year just on queen bees.
Current methods fall short of preventing honey bee loss and instead focus on coping with the fallout hive collapse.